How do you express yourself?

Using aggressive body language is a sign of an inability to find appropriate words to express your feelings. You might be angry and would like to convey it, but can it be done without raising your voice or being aggressive? Can the displeasure be expressed in a mild voice? Yes, if one has good command over language, it is possible to convey, with the use of appropriate words, any emotions.
But the point is whether the person to whom it is directed will get the message. There are both extremes - people who shout unnecessarily to show their temper and people who don't understand displeasure unless conveyed in strong words. If soft language is used with a person with less sensitivity towards others' feelings, it won't work. Similarly, if a person uses harsh language to a very sensitive person, it may have serious results. This means both sides have scope to mildly down - to become milder by the angry people and to become more sensitive to the thick-skinned people. Unless there is a match, it is impossible to communicate displeasure properly.
What happens when you take a very strict approach with extra sensitive people? If you yell at them, they might break down, become nervous and be afraid of you. On the contrary, if you use a very mild tone with non-sensitive people, they won't even bother about your irritation. There you have to raise your voice, redden your eyes and be strict as well as clear. But overdoing any of them, either being too loud or being too subtle, may result in failure of communication.
While at the receiving end, it is also important to be balanced in handling the fury. If the person is expressing themselves in a very strong way, you need to filter it yourself and not be affected adversely by the blatant language. If someone is rather more polite and subtle, you need to pay more attention to each word and take them seriously, rather than compelling her/him to take the strong approach. Not paying enough attention to your language while you are annoyed, and not being attentive to the language of other people when s/he is enraged, will result in a serious failure of communication.
So, observe how you express your anger next time.